Morphological characterization and pollen evaluation of some Tunisian ex situ planted caprifig (Ficus carica L.) ecotypes

Caprifig has a particular interest in plant conservation due to their important role in fig pollination. In this work, 53 morphological traits and four pollen descriptors were studied in order to select the most discriminating traits. Significant difference among ecotypes was revealed for almost quantitative traits except for anther number/flower and pollen viability. Qualitative data showed morphological variation within ecotypes (Blastophaga richness, external color, internal color, leaf color, central shape lobe, number lobe, tree growth habit, density branch, aspect branch and size tree). The results of the principal component analyses (PCA) for the morphological traits and pollen descriptors indicated that the first three PCs explained 54.23% of the total variation. Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis based on the similarity matrix grouped studied ecotypes in five clusters. It was possible to discriminate seven distinct ecotypes (Magouli1, Magouli2, Dhokkar1, Dhokkar4, Bouharrag1, Bouharrag2, and Bithri1). Similarly, some ecotypes sharing some fruit and shoots traits (Dhokkar2 and Dhokkar3) or some leaves and shoots characteristics (Bouharrag1, Assafri and Jrani) were grouped together. Some homonyms were detected between ecotypes such as Magouli, Bithri, Bouharrag and Dhokkar. Our study suggests among the 53 morphological traits and the four pollen descriptors 40 characters showed a good discriminating power and can be used for the discrimination of Tunisian caprifig trees.